Along with technology development, mobile terminals, such as a mobile phone, a PDA, a PMP, a navigator, and a laptop, additionally provide the functions, such as a DMB, a wireless internet, a near field communication between the devices, in addition to fundamental functions, such as call, video/music playbacks, and navigation. Accordingly, the mobile terminals include a plurality of antennas for a wireless communication, such as a wireless internet and a Bluetooth.
In addition, there is a recent trend that the functions, such as information exchange between the terminals, payment, ticket reservation, search, using a near field communication (i.e., a NFC, a Magnetic Secure Transmission (MST)) are applied to the mobile terminals. For this purpose, the mobile terminal is mounted with an antenna module for the mobile terminal (i.e., a NFC antenna module) used in a near field communication method. In this case, the NFC antenna module used is one of an electronic tags (RFID), and as a non-contact type near filed communication module using a frequency band of about 13.56 MHz, sends data between the terminals at a short distance of about 10 cm. The NFC, other than payment, is widely used for transmission of product information at a supermarket or a store and travel information for a visitor, transportation, a lock device for access control and the like.
Recently, there is a trend that a cover of a metal material (hereinafter, a metal cover) is increasingly applied to a mobile terminal, such as a tablet, a mobile phone. In this case, as illustrated in FIG. 1, in the case that the whole of a rear cover 11 of the mobile terminal is formed with a metal material, there is a problem that it is difficult to implement performance of a NFC antenna 13 mounted on a main body 12 of the mobile terminal. Accordingly, the research for implementing performance of the NFC antenna continues to proceed.
As an example, as illustrated in FIG. 2, a conventional mobile terminal 20 to which a metal cover 21 is applied forms a slit 22 (or an opening portion) on the metal cover for implementing performance of a NFC antenna, and mounts the NFC antenna in order to partially overlap with the slit 22. Accordingly, it is possible to implement performance of the NFC antenna through a coupling effect between the NFC antenna and the metal cover through the slit 22.
However, in case of forming a slit or an opening portion for implementing performance of the NFC antenna, there are the problems in that a manufacturing process of a mobile terminal becomes complicated to thus increase manufacturing costs, and the limitation that should reflect a slit or an opening portion in an exterior design occurs.
Meanwhile, as illustrated in FIGS. 3 and 4, as the user circumstance of the mobile terminal recently becomes various, a user demand for a structure that can perform a near field communication in a vertical direction (i.e., a side surface of the mobile terminal) as well as in a horizontal direction (i.e., a rear surface of the mobile terminal) is increasing.
However, as illustrated in FIG. 5, since a conventional NFC antenna 30 is formed with the shape winding a coil pattern 32 on an upper surface of a ferrite sheet 31, there is a problem in that it is difficult to implement antenna performance in a vertical direction.